


In Heat

by TaeFansick



Category: Invader Zim
Genre: Alien Sex, M/M, Oneshot, heat - Freeform
Language: English
Status: Completed
Published: 2019-09-18
Updated: 2019-09-18
Packaged: 2020-10-20 22:01:47
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,987
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20682614
Author URL: https://archiveofourown.org/users/TaeFansick/pseuds/TaeFansick
Summary: Originally posted on FFNThe title should be self-explanatory





	In Heat

Keef couldn't help looking to the empty desk in the front corner of the room. It made him curious. Where was his beloved green-skinned beauty? He sighed, running a hand over the orange chin curtain he had grown out over the last year. Actually, that wasn't the only modification to his appearance. He had also added a silver stud below his lower lip and added some emphasis to his green eyes, using some liner he bought.

He stretched, feeling restless. He looked to the clock above the board, ignoring Ms Bitters ranting about doom and whatnot. Normally he'd be taking notes and doodling pictures of Zim, looking to the other for a living model for each little sketch. His notebooks were filled with little Zims...But today he just wanted things to be over. This was the seventh day in a row that Zim had skipped. Was he sick? Keef frowned, not liking the idea of Zim having a cold with no one to take care of him. He remembered that when he was younger and in Zim's house, there had been no parents there, even though Zim would deny the claim, saying, of course, he had parents.

Once the bell finally rang, signalling the end of the day, Keef lept up, holding his messenger bag to him and rushing up to the front row where Dib was still gathering his own things. Dib wasn't exactly a friend, but Keef knew that Dib spent a lot of time around Zim, so if anyone knew anything, it would be the raven-haired youth. "Hey, Dib. Got a minute,"

"No," Dib ground out. He despised Keef.

Keef ignored the rude answer and just kept talking. "I was wondering if you'd spoken to Zim lately. Is he sick? Do you know when he's coming back to class?"

"How should I know?" Dib asked, rolling his eyes and beginning to leave. "We aren't friends,"

Keef frowned at that and followed Dib out. "You mean you haven't been to see him at all? What if he's injured and couldn't get to a doctor?"

"He has a phone, Keef," Dib reminded the red-head. "If you're so worried, then why don't you go over there yourself?"

Because I don't trust myself not to touch him. Keef had had a crush on Zim for years. He was constantly thinking about the foreign beauty. Zim, however, did not seem to feel the same and insisted on pushing Keef away. He was pretty certain that going to Zim's house would only annoy said, violet-eyed teen. "I guess I could...But I don't think he'd like that," Keef admitted.

"Of course he wouldn't," Dib confirmed. "But at least then you'd know, right?"

Keef nodded. Seemed like going was the only way he'd find anything out.

Oooo

Zim whimpered, his pink eyes clenched shut as he lay on his unmade bed, everything in disarray.

This was the week of his kind being in heat once their body is capable of bearing smeets. For years Zim never had to deal with it because he'd been too small to be able to bear smeets. Of course little over a year ago he had modified his PAK to help him grow so he could fit in normally with the growing humans in his class. He didn't take into account that this might happen.

He felt too hot all over. He had long since abandoned his boots and gloves since he secluded himself in his lab. He wasn't worried about Dib stepping in to disturb him because the big-headed Earth worm had been less and less active in his plans to expose Zim. Especially since Dib had found out that Zim's mission was a lie...

He didn't care about that right now. He just wanted this to be over. Once it hit midnight, the stars would go back out of alignment and Zim could go back to normal.

He glanced at the time and groaned. He still had several more hours of torture...

oooo

Keef looked to the time on his cell for the millionth time before glancing out his bedroom window. It was now dark out and he was still thinking about what Dib had said. He really did want to go see Zim...but he kept putting it off since he was sure Zim wouldn't want to see him.

Huffing, Keef buried his face in his crossed arms on his desk. He couldn't put it off any more...He'd done his homework, helped his little brother Meef with his, had dinner, did housework and his laundry...

"That's it. I'm going," he grumbled to himself, standing to get ready. He stepped into the bathroom and freshened up, styling his hair up into a fohawk and making sure his chin curtain was combed through. He even made sure to brush his teeth and face his face before moisturizing his face and hands. He had actually no idea why he was bothering but Zim made him so nervous. He didn't want Zim to be repulsed by anything he did or said. Sighing, he touched his eyes up with some liner before stipping himself of the shirt that he'd worn to class. He sprayed on some deodorant and went to his closet, fishing out some clean socks from the drawer and deciding on a black t-shirt to go with his fitted dark wash jeans.

Satisfied that he looked as good as he was able to at the moment, Keef slipped on his black converse and headed out, hoping he wasn't setting himself up just to get yelled at.

Oooo

It wasn't a long walk to Zim's house. Keef had memorized countless routes to the culdesac just to have a moment to pass by the odd green house, even though he never had the courage to step into the yard.

Feeling apprehensive still, Keef took several deep breaths before striding up to the front door and knocking. He stood silently, fidgeting. After what seemed like forever and he was thinking about either knocking again or leaving, the door opened, revealing a small silver and blue robot.

"HII~!" It waved very energetically up at Keef who hesitantly waved back.

"Um...Yeah...Hey...I came to see Zim...Is he here?" He looked into the house, not seeing his little obsession anywhere.

"Master's downstairs in his lab!" The robot answered. "I'm not allowed down there anymore," Not saying anything more, the small thing left and went to the couch, watching the large tv.

Keef frowned. "So...can I see him or not?"

"The Master cannot fight today," another voice spoke up, coming from above and making Keef jump.

Looking up nervously to see the source, Keef began thinking that this wasn't a good idea. "I don't want to fight...I was just worried about him," Keef spoke up. He felt stupid talking to a ceiling but...he didn't know who else to address. "He's been out of school for days..."

There was no answer right away. Finally, the ceiling spoke again. "You can go to the main lab. But if I receive the order, you'll either be terminated or ejected from the premises. Depending on Master's demands," At that, the floor opened on the other side of the room, revealing a platform. "Get on. I'll take you down,"

Keef just nodded dumbly. He'd forgotten how weird Zim's house could be.

Without a word, he stepped onto the platform, jumping in surprise as it lowered, taking him beneath the floor. In no time he was in an unfamiliar room he assumed was the lab because the platform quit moving.

"Go down the hall. Furthest door to the left is where the Master has been keeping himself," the ceiling spoke again.

"Thanks," Keef muttered, still a little freaked out. He just followed the directions he was given, wondering what on Earth Zim had been doing down here all week. Standing outside the door, he knocked. "Z-Zim? You in there?"

oo

Zim's eyes reopened and his lekku perked. Had he heard something? Zim groaned, whithering against the bed. No...Now he was hearing things in his fogged state...He turned on his side, burying his face into the pillow and immediately regretting it. He still felt too hot all over...He wanted relief so badly...

oo

Keef pressed his ear to the door, frowning. He was sure he'd heard something...He knocked again and listened harder. Yes! There was movement! Ah, man...Zim must be really sick to not be able to answer... "Zim? I'm coming in, okay?" When no objection came, Keef pressed against the door, trying to figure it out until it finally gave, whooshing open.

He looked around, noticing the large bed in the room and the comforter and pillows were strewn about. Finally, his eyes rested on a familiar form that was laying on the bed, Zim's back to Keef.

Keef, worried, crawled onto the bed quickly, a little panicked. Zim had actually been sick with no one to take care of him! He pulled Zim to lay against him and immediately Keef noticed the sweat on his forehead and how glazed Zim's eyes looked, lidded and unseeing. "Zim, are you okay?" He looked the form over, his brow furrowing. Where was Zim's hair...What were those things on his head?

Zim's lekku perked at the sound of Keef's voice and picked up the scent enveloping him now. It was so appealing..Where was it coming from? He looked up, seeing a vaguely recognizable face looking down at him. "K-Keef?"

Keef shivered, his eyes widening a bit. Zim's voice sounded so...husky. And those eyes...They weren't violet. They were a weird pink...almost bug-like with those...They must be antenna... Weirdly enough...it seemed to suit Zim much better. "Y-yeah...I'm here, buddy," he answered, his mouth suddenly very dry. "You weren't in school. I got worried,"

Zim barely heard any of it. He moved to nuzzle against Keef's form, purring. He liked how Keef smelled, how he felt...

Keef blushed at the contact, regretting that he had placed Zim's head against his lower stomach. "Z-Zim, maybe I could get you some cold water to drink...or s-some soup maybe?" He needed to get some space between them before he did something he regretted.

"No," Zim mewled, clinging to Keef's shirt to keep the red-head in place. Zim shifted to sit up, pressing more of his own form against Keef's, his other hand supporting himself on Keef's thigh. He nuzzled against Keef's neck, his lekku seeking out those of his new partner and finding nothing but soft dark orange fur. "Your fur feels soft," he muttered.

Keef's eyes fluttered at the contact and he craned his neck. It was like a dream come true having Zim be close to him like this. Normally the other hated being touched. "Ah...thanks," Keef replied, a stupid love-struck smile on his face.

Zim, unable to take the contact after all that time secluded, pressed his lips against Keef's bare neck, mewling at the softness. Encouraged, he began placing kiss after kiss at Keef's neck, wanting more contact.

Keef groaned. "Damn, Zim, I thought you were sick," His hands went to Zim's hips, kneading them gently.

Zim's hands drifted, moving under Keef's shirt and feeling a subtly muscled form. It wasn't so pronounced, but it was the body of a powerful swimmer since Keef had taken a liking to the sport. Being Irken, Zim groaned, loving the feel of strength. It was a craved trait in a mate among his kind and he was so pleased his partner met the standard in that area. "Oh Irk," Dazed and driven by instinct, Zim took the position of submissive to the taller one and moved to straddle Keef's lap, grinding down to gain some friction where he so desperately needed it and groaning loudly as a result.

Keef moaned, bucking up into the contact. He knew he should have stopped Zim...Should have left or something...but damnitt he'd wanted this for so long! And as long as Zim seemed willing, why waste an opportunity? He didn't care that Dib was right and that Zim was an alien. It didn't make Zim any less beautiful to Keef.

He smiled, grabbing the sides of Zim's face to make the pink-eyed beauty face him, Keef placing a loving and searing kiss against Zim's lips. Zim responded eagerly, licking at Keef's lip. Keep chuckled into the kiss, opening his mouth to sneak his tongue to dance along Zim's loving the taste of the other's long tongue.

Zim mewled, grinding his hips down again, earning a deep growl from Keef who pressed Zim back down to the bed, rolling his hips into Zim's. The other moaned in pleasure, bringing his own hips up to meet each press, widening his legs in further invitation.

Keef didn't need to be told twice and made quick work of kicking his own shoes and socks off before moving to pull Zim's leggings down and out of the way. He pressed his fingers in between Zim's legs, making the one below him squeal. Keef shivered in delight as he found Zim already wet and hard like he had been down there all that time, just waiting for him to come and claim the smaller one. He shifted his fingers, finding an opening that resembled a girl's and figured that must be normal for Zim's species..to have both that is.

Impatient, Keef pulled back to lift his top up and throw it to some random corner before doing the same to Zim's. Zim did nothing to aid or stop him, falling back to the bed and looking up at Keef with wanting eyes. There, naked and all splayed out, Keef nearly lost it. In a rush, he unbuttoned his jeans and yanked them down just enough to free his cock, moving back down, pressing the head of his erection against Zim's opening.

Zim spread his legs even more for his new partner, tossing his head back in pleasure. "In...I need it in, please," he begged, squirming wantingly.

Keef smiled, licking at Zim's neck as he slowly pressed in, gasping at how tight and wet Zim felt around him. He heard Zim moan in approval and pressed in deeper, not wanting to hurt Zim any. As Zim was stretched further, he began to whimper, tears forming in the corner of his eyes. Keef kissed them away, trying to soothe the other.

After what felt like an eternity of staying still in the welcoming heat, Keef gave an experimental rock of his hips, making Zim moan loudly and cling to Keef's shoulders. Keef hissed at the bittersweet feel of claws in his shoulders and thrusted again, Zim moving to meet him this time. "Damnitt, you feel good, Zim," Keef ground out. He thrusted again and again, picking up the pace. Each movement caused Zim to moan and gasp, still squirming sensually as he tried to meet each touch.

Zim's head tossed back and forth as his thought process left him. He didn't care that Keef was the one above him. He didn't even care that it was a human that was inside of him, giving him this amazing feeling. All he knew was that he had wanted this for so long and now he finally had it.

Still...he needed more. Zim growled lowly, startling Keef. "Deeper," Zim forced out. "I need more...Harder!"

Keef nearly came right then but was able to hold back. Not wanting to deny his love, he pulled back and thrust as hard and deep as he could, earning a scream to rip from Zim's throat, his eyes shooting wide open. Grinning like a maniac, Keef kept going, keeping the new pace up, fast and hard, loving how Zim was reacting.

Zim grabbed at the bed below and dug his claws clear through the bedding. His back arched as he bucked harshly and impatiently up to meet each moment of this delicious friction. He could feel himself coming closer and closer to completion. He wrapped his legs around Keef's waist, using it as leverage to keep Keef pressed as deep as possible in him.

Keef caught on and moved to stroke Zim's neglected member, pumping it hard and fast as he kept moving inside of the alien.

Both of their gasps came faster, the air around them hotter than they thought possible. Feeling close to the edge, Keef bit his lip to try and hold back, moving his hand fast against the very tip of Zim's cock.

Zim screamed even louder than before, his entire body seizing up as he came hard, bucking violently as he rode out the amazing feeling. Keef, feeling the tightness around him increase even more and seeing the look of absolute bliss on Zim's face, finally came deep inside of his love, yelling Zim's name out.

Finally, they calmed down. Keef pulled himself from Zim's entrance, noting that Zim's own erection had gone inside of him. He didn't think much of it, instead stroking against Zim's face. "Hey, buddy...How ya feelin' now?"

Zim's eyes slowly became more focused. He blinked until he could make out Keef's form above his. Still trying to calm himself, Zim did a mental check of his position, realizing that yes, he did indeed allow a human to defile him. And yet he couldn't find it in him to care all that much. At least it was the human that tried to be on his good side rather than the one that tried to slice him open. "Yes, I'm fine...Sorry to...bring you into this,"

Keef smiled. "Oh, it was no trouble on my part. I wouldn't mind doing it again, actually,"

Zim looked at Keef incredulously for a moment before he let a small smile reach his lips. "Again, huh...What a strange human you are..."


End file.
